Stabilization of sulfurized hydrocarbons



March 13, 1956 D, T. ROGERS ET AL 2,738,344

STABILIZATION OF SULFURIZED HYDROCARBONS Filed Sept. 22, 1951 LOT OFCOPPER Vs. I-IospI-Iozus CloNTEN-rs F'oa dumzous Oxma- TREATED SuwumzanHYDIZOCAIZbONS oppaw. In IzoDuc-r, WEIGHT "/0 r- !\7 (P o o 0 I l l l ll 0 L0 2.0 5.0 4.0 HQfiPl-KQRLJS m szooucr, WEIGHT 7:

13 Zw rib. T. 20 QIQEQ 1 ms zawgfgi fln-vmbors filbbornag United StatesPatent STABILIZATION 0F SULFURIZED HYDROCARBONS Dilworth T. Rogers,Summit, and John P. McDermott,

Roselle, N. J., assignors to Esso Research and Eng:- neering Company, acorporation of Delaware Application September 22, 1951, Serial No.247,808

7 Claims. (Cl. 260-139) The present invention is related to an improvedmethod for preparing sulfurized hydrocarbons. More specifically, it isconcerned with a treating process for preparing sulfurcontaininghydrocarbons having improved product quality.

Sulfurized hydrocarbons prepared, for example, by treatment ofhydrocarbons with elemental sulfur or reactive sulfur compounds, such assulfur halides, sulfides of phosphorus, and the like, are extremelyvaluable additives for various hydrocarbon products. They areparticularly useful as anti-oxidants, detergents, and corrosioninhibitors for various types of lubricants. The sulfurization step,however, frequently results in the formation of products that areunstable with respect to HzS evolution on storage, that may be corrosiveto certain types of metals, or that have poor color. It is known toneutralize the acidity in the sulfurized materials bytreatment withcertain basic reagents, particularly metal-containing reagents,resulting in the formation of compounds containing a metal component.Such treatment does not always achieve the desired stabilization and, inaddition, is undesirable when the finished product is to be ashless innature.

It is a principal object of the present invention to disclose a novel,inexpensive process for treating unstable and corrosive sulfurizedhydrocarbons whereby substantial improvements in product quality areobtained. This invention also teaches a method for treating suchhydrocarbons with a metal compound whereby the amount of metalconstituent introduced into the finished product is controlled.

In accordance with the present invention, the reaction product of sulfuror of a reactive sulfur compound with an essentially hydrocarbonmaterial is treated with a minor amount of cuprous oxide at an elevatedtemperature under conditions whereby the product is stabilized. Thetreating process is preferably carried out with a sulfurized hydrocarboncontaining no or only a relatively small amount of phosphorus since ithas been found that the substantially phosphorus-free sulfurizedhydrocarbons do not retain chemically-combined copper as a result of thetreatment.

The mechanism whereby the reaction products are improved by treatmentwith cuprous oxide is not entirely understood, particularly since cupricoxide is substantially inefiective for producing the desired results.Possibly since cuprous oxide is a reducing agent and cupric oxide is anoxidizing agent, only the former compound will effect reaction with orconversion of the types of unstable compounds present.

The cuprous oxide is preferably added to the material to be treated as afinely divided solid, such as powder, pellets, or the like. The oxideand sulfurized hydrocarbon are preferably stirred during thecontactingstep at an elevated temperature for a time sufiicient to effect theimprovements desired. The treating temperature should be above about 150F. and below about 450 F. to 500 F. in order to eifect substantialimprovements and yetprevent substantial decomposition of the sulfurizedhydrocarbons. A preferable temperature range is about 200 to 400 F.

The amount of cuprous oxide employed will vary depending on the contacttime and treating temperature. Amounts below about 0.5 wt. percent,based on the material being treated, will generally require rathersevere treating conditions, whereas it is generally uneconomical to useamounts much higher than about 20 to 25 wt. percent. Preferred amountsare in the range of about 1 to 15% by weight. Treating times aregenerally not critical and will depend to a large extent on the type ofstock being treated, the amount of cuprous oxide employed, and thetreating temperature. Contact times may vary from about five minutes upto about ten hours or more, preferably in the range of about 0.5 to 5hours.

After the treatment has been carried out for the desired length of time,the solid material is removed by filtration of the hydrocarbonderivative through a diatomaceous earth such as Hy-Flo or through otherequivalent filtering or separation means to recover a substantiallysolid-free material. The resulting stabilized product is then ready foruse as such or may be further reacted with various materials to producederivatives having certain desired characteristics.

The term sulfurized hydrocarbon as used herein refers to materialsprepared by reaction of an essentially hydrocarbon material with areactive sulfur-containing material including elemental sulfur,elemental sulfur and phosphorus mixtures, a sulfide of phosphorus suchas P285, P453, P487, ormixtures thereof, or with sulfur halides such assulfur monochloride, sulfur dichloride, mixtures of these materials andthe like. If desired, the material may be reacted with sulfur in a firststep and subsequently reacted with a sulfide of phosphorus before thetreatment with cuprous oxide is carried out. The sulfurized hydrocarbonpreferably comprises at least 1.0 weight percent of chemically combinedsulfur.

The essentially hydrocarbon materials used in preparing the sulfurizedhydrocarbon may be paraflins, olefins or olefin polymers, diolefins,acetylenes, aromatics or alkyl aromatics, cyclic aliphatics, petroleumfractions such as lubricating oil fractions, petrolatums, waxes, crackedcycle stocks, condensation products of petroleum fractions, solventextracts of petroleum fractions, and the like. Bright stock residuumsand lubricating oil distillates are particularly desirable hydrocarbonsto be employed. The foregoing hydrocarbons may be condensed, usuallythrough first halogenating the hydrocarbon, with aromatic hydrocarbonsin the presence of anhydrous inorganic halides such as aluminumchloride, zinc chloride, etc.

As examples of mono-olefins may be mentioned isobutylene, decene,dodecene, cetene (C16), octadecene (C18), cerotene (C26), melene (C30),olefinic extracts from gasoline or gasoline itself, cracked cycle stocksand polymers thereof, cracked waxes, dehydrohalogenated chlorinatedwaxes, and any mixed high molecular weight alkenes obtained by crackingpetroleum oils. A preferred class of olefins are those having at least20 carbon atoms per molecule, of which from about 12 to about 18 carbonatoms, and preferably at least 15 carbon atoms, are in a long chain.Such olefins may be obtained by the dehydrogenation of paraffin waxes,by the dehydrohalogenation of long chain alkyl halides, by the synthesisof hydro carbons from C0 and H2, by the dehydration of alcohols, etc.

Another class of suitable olefinic materials are the terpenes such asdipentene and the like. The monoolefin polymers, in which the molecularweight ranges from to 50,000, preferably from about 250 to about 10,000may also be used. These polymers may be obtained by the polymerizationof low molecular weight mono-olefinic hydrocarbons, such as ethylene,propylene, butylene, isobutylene, normal and isoamylenes, or hexenes, orby the copolymerization of any combination of the above mono-olefinicmaterials.

Diolefins which may be employed include well known materials such asbutadiene, isoprene, chloroprene, cyclopentadiene,2,3-dimethylbutadiene, pentadiene-1,3, hexadiene-2,4, terpenes and thelike. Acetylene and substituted acetylenes may similarly be employed.

Another class of unsaturated hydrocarbon materials which may beadvantageously employed in the preparation of the additives of thisinvention are high molecular weight copolymers of low molecular weightmono-olefins and diolefins. The copolymer is prepared by controlledcopolymerization of a low molecular weight olefin and a non-aromatichydrocarbon having the general formula CnHZn-z, in which x is 2 or amultiple of 2, in the presence of a catalyst of the Friedel-Crafts orperoxide type. The low molecular weight olefin is preferably anisoolefin or a tertiary olefin, preferably one having less than 7 carbonatoms per molecule. Examples of such olefins are isobutylene,Z-methyIbutcne-l, Z-ethylbutene-l, secondary and tertiary base amylenes,hexylenes, and the like. Examples of the non-aromatic hydrocarbons ofthe above formula which may be used are the conjugated diolefins listedin the preceding paragraph, diolefins such as 1,4-hexadiene, in whichthe double bond is not conjugated, as well as the acetylcnes. Thecopolymerization is preferably carried out in the presence of aluminumchloride, boron fluoride, or benzoyl peroxide, and the copolymer ispreferably one having a molecular weight of about 1,000 to 30,000.Specifically preferred limits are between about 1,500 and 20,000molecular weight.

Another class of hydrocarbons which may be employed in a similar mannerare aromatic hydrocarbons, such as benzene, naphthalene, anthracene,toluene, xylene, diphenyl, and the like, as well as aromatichydrocarbons having alkyl substituents and aliphatic hydrocarbons havingaryl substitutents.

A still further class of hydrocarbons which may be employed in thereaction are condensation products of halogenated aliphatic hydrocarbonswith an aromatic compound, produced by condensation in the presence ofaluminum chloride or other Friedel-Crafts type catalyst. The halogenatedaliphatic hydrocarbon is preferably a halogenated long chain paraffinhydrocarbon having more than 8 carbon atoms, such as parafiin wax,petrolatum, ozocerite wax, etc. High viscosity parafiin oils,particularly heavy residual oil which has been treated with chemicals orextracted with propane or other solvents for the removal of asphalts,may be employed. The aromatic constituent may be naphthalene, fluorene,phenanthrene, anthracene, coal tar residues, and the like.

Another type of hydrocarbon material which may be similarly employed isa resin-like oil which has a molecular weight of from about 1,000 to2,000 or higher, obtained preferably from a parafiinic oil which hasbeen dewaxed and which is then treated with a liquified normally gaseoushydrocarbon, e. g. propane, to precipitate a heavy propane-insolublefraction. The latter is a substantially wax-free and asphalt-freeproduct having a Saybolt viscosity at 210 F. of about 1,000 to about4,000 seconds or more.

The reaction of the hydrocarbon material with sulfur or reactivesulfur-containing materials may be conducted by procedures well known inthe art. For example, the hydrocarbon may be treated with from about 1to by weight of free sulfur or of compounds of sulfur and phosphorus for2 to 15 hours or more at a temperature above 200 F. and up to about 500F. The resulting product, which will usually contain above 1 to 2 weightpercent of chemically combined sulfur, may then be filtered and blownwith nitrogen or otherwise treated to remove hydrogen sulfide or otherreaction gases. The

CLK

4 material may then be treated with cuprous oxide in accordance with theprocedure outlined above.

A particularly desirable procedure is to react hydrocarbons,particularly unsaturated hydrocarbons, with a sulfur halide followedpreferably by a dehydrohalogenation step, which may be accomplished bytreating the sulfurized and halogenated hydrocarbon product with phenolor other hydroxy compound. Such a method is described in the Winning andRogers U. S. Patent 2,422,275. It is preferred that the sulfurizedhydrocarbon be substantially free of halogen before conducting thecuprous oxide treating step.

The hydrocarbon material or one of the sulfurized hydrocarbons preparedby the above procedures may be sulfurized by treatment with a sulfide ofphosphorous at an elevated temperature such as in the range of about 300to 550 F., generally using about 1 to 3 molecular proportions ofhydrocarbon to at least /3 molecular proportion of phosphorus sulfide.Usually the reaction is carried out in a non-oxidizing atmosphere, suchas an atmosphere of nitrogen above the reaction mixture. An amount ofphosphorus sulfide is usually used that will completely react with thehydrocarbon under the conditions used. Reaction times in the range ofabout 2 to 10 hours will generally be required, although the reactiontime is not critical. The resulting reaction product may be furthertreated by blowing with steam, alcohol, or the like to improve odorbefore treatment with the cuprous oxide, although treatment with theoxide will generally be sufficient to improve odor without thisintermediate step. Other sulfurization procedures known to the art maybe used.

Cuprous oxide treatment effects substantial improvements in sulfurizedhydrocarbons obtained by various sulfurization methods. However,phospho-sulfurization introduces acidic compounds that are quitereactive with the cuprous oxide, resulting in the formation oforganocopper compounds which are ash-forming in nature. It has beenfound on the other hand that sulfurized hydrocarbons containing lessthan about 1 wt. percent phosphorus, preferably below 0.5 Wt. percentphosphorus. will have extremely low copper contents such as below 0.5 to0.2 wt. percent copper. In addition, improvements with respect tostability, odor, color, and the like are sometimes greater in the caseof materials containing relatively small amounts of phosphorus.sulfurized hydrocarbons containing no phosphorus have been found to besubstantially entirely free of copper, even after treatment under rathersevere conditions with cuprous oxide. Therefore, cuprous oxide treatmentof substantially phosphorus-free materials or those containing only alimited amount of phosphorus is preferred, particularly when an ashlessdetergent is desired.

The additives of the present invention are particularly suitable for usein lubricating oils, and when used for such purpose must be sufiicientlysoluble to accomplish the desired improvements in the finishedcomposition. Proportions of about 0.001 to about 20.0 wt. percent,generally not above about 10%, of the treated sulfurized hydrocarbonwill generally be used in the lubricating oil. Obviously the proportionswill vary depending somewhat on the nature of the additive and thespecific purpose which the lubricant is to serve in a given case. Forcommercial purposes it is convenient to prepare concentrated oilsolutions in which the amount of additive in the composition ranges fromabout 20 to 50% by weight, and thus transport and store them in suchform. Since the concentrates may be stored for extended periods of time,the treating step of the present invention is quite beneficial from thestandpoint of preparing a stable and more saleable product.

Below are given detailed descriptions of preparations of sulfurizedhydrocarbons prepared and treated in accordance with the presentinvention. It is to be understood that the examples are given asillustrations only and are not to be construed as limiting the scope ofthe invention in any way.

Example 1 Product A was prepared by combining and heating a mixture of1000 g. of a Mid-Continent lubricating oil having a Saybolt viscosity at210 F. of 56 seconds and 150 g. (15.0 weight percent) of sulfur at atemperature of about 420 F. The sulfurization step was continued for 6hours with rapid stirring and nitrogen blowing. After cooling to about212 F. the product was filtered through Hy-Flo and a dark, viscousconcentrate was obtained which contained 3.7 weight percent sulfur.

Product B was prepared by treating 270 g. of Product A with 30 g. 11.1weight percent) of powdered cuprous oxide for 3 hours at a temperatureof about 390 F. The mixture was stirred rapidly and blown with nitrogenduring the reaction period. Solids were removed from the product byfiltration through Hy-Flo. The product contained about 0.04 weightpercent copper.

Product C was prepared in the same way as Product B except that 30 g.(11.1 weight percent) of cupric oxide were employed in place of cuprousoxide. The filtered product contained 0.02 weight percent copper.

Each of the Products B and C was blended in a lubricating oil baseconsisting of a solvent extracted Mid- Continent distillate of SAE 10grade. Each blend contained 1.0 weight percent of the active ingredientin the oil.

modification of the C. R. C. method 11-16-445. This method comprisesimmersing a polished metallic copper strip in the oil blend to be testedfor 3 hours at 212 F. and noting the extent of staining. Numericalratings from 1 to 10 denote discoloration ranging from no stain to ablack surface film, respectively. The results of the tests are givenbelow:

Product Used in Oil: Copper strip rating A (no treatment) 10 B (CuaOtreatment) 2 4 These blends and a sample of the unblended base. oil weresubmitted to a copper, strip test which was a C (CuO treatment) 10 It isnoted that cupric oxide is inelfective as a treating agent for reducingthe corrosiveness of the sulfurized hydrocarbon whereas cuprous oxideunder the conditions used was extremely effective.

Example ll Product D was prepared as follows: 56 pounds of sulfur, 1.87pounds of mercaptobenzothiazole and 0.93 pound of diphenyl guanidinewere placed in a glass lined reactor with reflux condenser and heated to300 F. 131 pounds of commercial dipentene were added gradually over aperiod of about one hour at 300 F. The temperature was then raised to350 F. and held at this point for 6 hours, after which the product wascooled. Upon analysis it was found to contain 23.0 Weight percentchemically combined sulfur. Three portions of the resulting sulfurizeddipentene were treated respectively, with 0.5, 1.0, and 2.0 weightpercent, based on the material being treated, of cuprous oxide. Eachtreatment was carried out at a temperature of about 185 to 200 F. for 10minutes, following Which'the products were filtered through Hy-Flo. Thestorage stability of the untreated sulfurized dipentene and of each ofthe treated products was determined as follows:

Four-ounce bottles were filled about /1. full with the product,stoppered with tin foil-covered corks, and stored for 20 hours at atemperature of 140 F. The stoppers were then removed, and a filter paperthat had been dipped in saturated lead acetate solution just prior tothe test was immediately placed over the bottle opening being held inplace by means of a watch glass. After five minutes the test papers wereremoved and allowed to dry, followed by rating against a set ofstandards in which zero represents no stain and 10 represents a heavyIblack metallic stain. The results of this test are shown elow:

C1120 Treatment of Sulfurized Dipentene, Weight Percent H25 Rating HONOQO Substantial improvements in odor and storage stability wereobtained by treatment with small amounts of cuprous oxide. 0.5 weightpercent cuprous oxide was not suflicient to produce an entirely stableproduct under the temperature and time conditions employed.

Example III Product E, consisting of sulfurized di-isobutylene, wasprepared as follows:

To 2520 g. of di-isobutylene contained in a 4-necked, 5 liter flaskequipped with a stirrer, thermometer, reflux condenser, and droppingfunnel, were added 1050 g. of sulfur monochloride over a period of about1% hours. The initial temperature was 78 F., but upon completion of thesulfur halide addition the reaction temperature had risen to F. Thereaction mixture was then heated at this temperature for an additional30 minutes. 138 g. of phenol were then added, and after the phenoldissolved, the flask was equipped with a downward condenser and thetemperature raised to 220 F. Vacuum was gradually applied, and thetemperature maintained at 220 F. for 6 hours, after which distillationhad practically ceased. The resulting product was dissolved in an equalvolume of oil, which concentrate contained 13.0 percent S andessentially no chlorine.

Product F was prepared by treating 500 g. of Product E with 25 g. (5weight percent) of cuprous oxide at 212 F. with stirring. The materialwas then soaked at a temperature of about 212 F.-230 F. for 2% hours,followed by filtration through Hy-Flo. The final product was a clear,light red concentrate. Products E and F were subjected to variouslaboratory tests. Sunlight stability was determined by storing productsin clear glass bottles under conditions whereby they were contacted bysunlight. Copper strip ratings were determined by the method describedin Example I. The results of these tests are shown as follows:

Product E F Sulfur Content, Weight Percent 13.0 12. 9 Copper Content,Weight Percent--- 0 0. 01 Sunlight Stability, Days to Form 11:17 4 35+Color, Robinson 1% 7 Copper Strip Rating 10 2 Product G was prepared asfollows: A 500 g. charge of Product E contained in a 3 necked, 1 literflask equipped with a stirrer, thermometer, and reflux condenser washeated to 203 F., followed by the addition of 50 g. of P483. Thetemperature was then maintained at 203212 F. for 2 hours with rapidstirring. At this stage, a practically clear, reddish liquid wasobtained with only a very small amount of insoluble residue. The productwas then steam distilled for one hour, after which it was poured into aseparatory funnel. The organic layer was withdrawn, blown with nitrogenfor 20 minutes at 212-221 F. to remove water, after which it wasdissolved in an equal volume of light mineral oil to give a 50%concentrate.

Product H was prepared as follows: 300 g. of Product G was heated toabout 176 F., after which 6.0 g. (2 weight percent) of cuprous oxidewere added with rapid stirring. After stirring for 2 hours at 221 F., 2%of acid-treated contact clay was added, followed by filtration throughHy-Flo. A dark red, practically odorless product was obtained, whichupon analysis was found to contain 0.54% copper, 1.4% phosphorus, and13.4% sulfur.

Product I was prepared in the same manner as described in thepreparation of Product G using 500 g. of Product E and 50 g. of P255.

Product K was prepared in the same manner as described in connectionwith the preparation of Product H using 300 g. of Product I and 6.0 g.(2 weight percent) of cuprous oxide. A very dark red, practicallyodorless material was obtained which, upon analysis, was found tocontain 0.08% copper, 0.33% phosphorus, and 14.7% sulfur.

Product L was prepared in the following manner: A lubricating oil brightstock derived from a Mid- Coutincnt crude, prepared by deasphalting,dewaxing, acid and clay treating the residuum, and having about 252seconds viscosity (Saybolt) at 210 F. was treated with 17.5 weightpercent of P255 for 7 hours at a ternperature of 400 F. The product wasthen filtered.

Product M was prepared by treating a portion of roduct L with weightpercent of commercial dipentene for l hour at 380 F. temperature inorder to obtain the dipentene derivative thereof. The resultingderivative was then heated to about 360 F. with 5 weight percent CuzOfor 2 /2 hours with rapid stirring. The filtered product was clear, darkred, and viscous, and, upon analysis, was found to contain 2.7 weightpercent phosphorus, 4.6 weight percent sulfur, and 5.7 weight percentcopper.

Product N was prepared by treating a portion of Product L with 5 weightpercent of cuprous oxide at about 360 F. for 2 hours with rapidstirring. The filtered product contained 2.9 weight percent phosphorus,5.2 weight percent sulfur, and 2.9 weight percent copper.

H ratings were determined on the above products in accordance with theprocedure of Example Hi. The results are shown below:

H25 rating Product tested:

Exam 1 1.2 V

The corrosion and detergcncy characteristics of the products prepared asdescribed in the above examples were tested by laboratory bearingcorrosion and Lauson engine tests on the blends of the products invarious oils. The tests were conducted substantially in accordance withthose described in Examples 12 and 13 of U. S. 2,529,303 to Mcfiermott.The bearing corrosion test was carried out using a blend containing 0.25weight percent of the additive in a solvent extracted, Mid-Continentparaflinic lubricating oil of SAE 20 grade, the test being carried outon the base oil as such also. 0.5 weight percent of the products wereblended in a solvent extracted Mid- Continent SAEl0 grade oil and testedalong with the base oil per se in 20 hour Lauson engine runs, the enginebeing operated at 290 F. jacket temperature and 300 F. oil temperature.hc results of these tests are shown below:

Some improvement in bearing corrosion and detergency characteristicswere obtained by the cuprous oxide treatment.

Example VI The copper and phosphorus contents of the variousCuzO-treated products prepared as shown above are plotted in Figure 1.Chemically combined copper was not present in the treated productsderived from substantially phosphorus-free sulfurized hydrocarbonscontaining up to about 15 weight per cent sulfur whereas the coppercontent showed a sharp increase when the material treated containedabove 0.15-1.0 weight per cent phosphorus. The substantially copper-freematerials are particularly useful as ashless detergents in aviationengine lubricating oils and the like.

The products of the present invention may be employed in ordinaryhydrocarbon lubricating oils, the heavy duty type of lubricants alongwith other additives of the conventional type, and with varioussynthetic lubricants such as those prepared by polymerization ofolefins, by the reaction of oxides of carbon with hydrogen, or by othermeans. The conventional synthetic oils of the ester, poly-ester andpoly-ether types may also be used alone or in combination with minerallubricants as base oils. The lubricating oils may vary considerably inviscosity and other properties, depending on the use for which they aredesired, but they usually range from about 40 to seconds viscosity(Saybolt) at 210 F.

Other agents such as dyes, pour depressors, organometallic compounds,sludge disperser, viscosity index improvers, and the like may be usedalong with the additives of the present invention in compoundinglubricants. In addition to being employed in lubricants, the additivesof the present invention may also be used in motor fuels, hydraulicfluids, cutting oils, turbine oils, fuel oils, transformer oils, and inother petroleum products susceptible to oxidation. They may also be usedin gear lubricants and greases.

What is claimed is:

1. A method for preparing improved sulfur-containing hydrocarbonproducts which comprises reacting a hydrocarbon material with at leastone agent selected from the group consisting of sulfur, sulfides ofphosphorus and sulfur halides to form a sulfurized hydrocarboncontaining at least 1.0 weight percent of chemically combined sulfur andless than about 1.0 weight percent phosphorus, treating said sulfurizedhydrocarbon with cuprous oxide in an amount in the range of about 0.5 to25% by weight, based on the sulfurized hydrocarbon, at a temperature inthe range of about 150 to 500 F. for a period of time in the range ofabout 5 minutes to 10 hours, removing solids from the cuprousoxide-treated sulfurized hydrocarbon, and recovering a substantiallycopper-free, sulfurcontaining hydrocarbon product.

2. The method as in claim 1 wherein said product is formed by reacting amineral lubricant base stock with sulfur.

3. The method as in claim 1 wherein said product is formed by reacting amineral lubricant base stock with a sulfide of'phosphorus.

4. The method as in claim 1 wherein said product is formed by reacting aterpene with sulfur.

5. The method as in claim 1 wherein said product is a substantiallyhalogen-free reaction product of an unsaturated hydrocarbon and a sulfurhalide.

6. The method as in claim 5 wherein said dehalogenated reaction prodctis further reacted with a sulfide of phosphorus before treating withsaid oxide.

7. A method for preparing improved sulfur-containing hydrocarbonproducts which comprises reacting a hydrocarbon material with at leastone agent selected from the group consisting of sulfur, sulfides ofphosphorus and sulfur halides to form a sulfurized hydrocarboncontaining at least 1.0 weight percent of chemically combined sulfur andless than about 0.5 weight percent phosphorus, treating said sulfurizedhydrocarbon with cuprous oxide in an amount in the range of about 1 to15% by weight, based on the sulfurized hydrocarbon, at a temperature inthe range of about 200 to 400 F. for a period of time in the range ofabout 0.5 to 5 hours, removing solids from the cuprous oxide-treatedsulfurized hydrocarbon, and recovering a substantially copper-free,sulfur-containing hydrocarbon product.

References Cited in the file of this patent UNITED STATES PATENTS2,080,365 von Fuchs May 11, 1937 2,174,810 von Fuchs Oct. 3, 19392,422,275 Winning et a1. June 17, 1947 2,489,249 Adelson Nov. 29, 19492,560,547 Bartleson July 17, 1951

1. A METHOD FOR PREPARING IMPROVED SULFUR-CONTAINING HYDROCARBONPRODUCTS WHICH COMPRISES REACTING A HYDROCARBON MATERIAL WITH AT LEASTONE AGENT SELECTED FROM THE GROUP CONSISTING OF SULFUR, SULFIDES OFPHOSPHOROUS AND SULFUR HALIDES TO FORM A SULFURIZED HYDROCARBONCONTAINING AT LEAST 1.0 WEIGHT PERCENT OF CHEMICALLY COMBINED SULFUR ANDLESS THAN ABOUT 1.0 WEIGHT PERCENT PHOSPHOROUS, TREATING SAID SULFURIZEDHYDROCARBON WITH CUPROUS OXIDE IN AN AMOUNT IN THE RANGE OF ABOUT 0.5 TO25% BY WEIGHT, BASED ON THE SULFURIZED HYDROCARBON WITH CUPROUS OXIDETHE RANGE OF ABOUT 150* TO 500* F. FOR A PERIOD OF TIME IN THE RANGE OFABOUT 5 MINUTES TO 10 HOURS, REMOVING SOLIDS FROM THE CUPROUSOXIDE-TREATED SULFURIZED HYDROCARBON, AND RECOVERING A SUBSTANTIALLYCOPPER-FREE, SULFURCONTAINING HYDROCARBON PRODUCT.